separate metadata/upload into separate files, handle mime types safely, preserve names on download (only)

This commit is contained in:
mappu 2017-10-06 20:19:02 +13:00
parent 5885b58dcd
commit dfc86893a2
3 changed files with 143 additions and 99 deletions

45
Metadata.go Normal file
View File

@ -0,0 +1,45 @@
package contented
import (
"encoding/json"
"os"
"time"
"github.com/boltdb/bolt"
)
type Metadata struct {
FileSize int64
UploadTime time.Time
UploadIP string
Filename string
MimeType string
}
func (this *Server) Metadata(fileID string) (*Metadata, error) {
var m Metadata
err := this.db.View(func(tx *bolt.Tx) error {
content := tx.Bucket(this.metadataBucket).Get([]byte(fileID))
if len(content) == 0 {
return os.ErrNotExist
}
return json.Unmarshal(content, &m)
})
if err != nil {
return nil, err
}
return &m, nil
}
func (this *Server) SetMetadata(fileID string, m Metadata) error {
jb, err := json.Marshal(m)
if err != nil {
return err
}
return this.db.Update(func(tx *bolt.Tx) error {
return tx.Bucket(this.metadataBucket).Put([]byte(fileID), jb)
})
}

108
Server.go
View File

@ -1,17 +1,12 @@
package contented
import (
"crypto/sha512"
"encoding/hex"
"encoding/json"
"io"
"log"
"mime/multipart"
"net/http"
"os"
"path/filepath"
"strings"
"time"
"github.com/boltdb/bolt"
)
@ -55,99 +50,6 @@ func NewServer(opts *ServerOptions) (*Server, error) {
return s, nil
}
type Metadata struct {
FileSize int64
UploadTime time.Time
UploadIP string
Filename string
}
func (this *Server) handleUpload(src multipart.File, hdr *multipart.FileHeader, UploadIP string) (string, error) {
// Get file length
srcLen, err := src.Seek(0, io.SeekEnd)
if err != nil {
return "", err
}
_, err = src.Seek(0, io.SeekStart)
if err != nil {
return "", err
}
// Get file hash
hasher := sha512.New512_256()
_, err = io.CopyN(hasher, src, int64(srcLen))
if err != nil {
return "", err
}
_, err = src.Seek(0, io.SeekStart)
if err != nil {
return "", err
}
// Save file to disk
fileID := hex.EncodeToString(hasher.Sum(nil))
dest, err := os.OpenFile(filepath.Join(this.opts.DataDirectory, fileID), os.O_CREATE|os.O_WRONLY, 0600)
if err != nil {
if os.IsExist(err) {
return fileID, nil // hash matches existing upload
}
return "", err
}
defer dest.Close()
_, err = io.CopyN(dest, src, int64(srcLen))
if err != nil {
return "", err
}
// Persist metadata to DB
m := Metadata{
Filename: hdr.Filename,
UploadTime: time.Now(),
UploadIP: UploadIP,
FileSize: srcLen,
}
err = this.SetMetadata(fileID, m)
if err != nil {
return "", err
}
// Done
return fileID, nil
}
func (this *Server) Metadata(fileID string) (*Metadata, error) {
var m Metadata
err := this.db.View(func(tx *bolt.Tx) error {
content := tx.Bucket(this.metadataBucket).Get([]byte(fileID))
if len(content) == 0 {
return os.ErrNotExist
}
return json.Unmarshal(content, &m)
})
if err != nil {
return nil, err
}
return &m, nil
}
func (this *Server) SetMetadata(fileID string, m Metadata) error {
jb, err := json.Marshal(m)
if err != nil {
return err
}
return this.db.Update(func(tx *bolt.Tx) error {
return tx.Bucket(this.metadataBucket).Put([]byte(fileID), jb)
})
}
func (this *Server) handleView(w http.ResponseWriter, r *http.Request, fileID string) error {
// Load file
f, err := os.Open(filepath.Join(this.opts.DataDirectory, fileID))
@ -163,7 +65,15 @@ func (this *Server) handleView(w http.ResponseWriter, r *http.Request, fileID st
return err
}
http.ServeContent(w, r, m.Filename, m.UploadTime, f)
// ServeContent only uses the filename to get the mime type, which we can
// set accurately (including blacklist)
w.Header().Set(`Content-Type`, m.MimeType)
if m.MimeType == `application/octet-stream` {
w.Header().Set(`Content-Disposition`, `attachment; filename="`+m.Filename+`"`)
}
http.ServeContent(w, r, "", m.UploadTime, f)
return nil
}

89
upload.go Normal file
View File

@ -0,0 +1,89 @@
package contented
import (
"crypto/sha512"
"encoding/hex"
"io"
"mime"
"mime/multipart"
"os"
"path"
"path/filepath"
"strings"
"time"
)
func (this *Server) handleUpload(src multipart.File, hdr *multipart.FileHeader, UploadIP string) (string, error) {
// Get file length
srcLen, err := src.Seek(0, io.SeekEnd)
if err != nil {
return "", err
}
_, err = src.Seek(0, io.SeekStart)
if err != nil {
return "", err
}
// Get file hash
hasher := sha512.New512_256()
_, err = io.CopyN(hasher, src, int64(srcLen))
if err != nil {
return "", err
}
_, err = src.Seek(0, io.SeekStart)
if err != nil {
return "", err
}
// Save file to disk
fileID := hex.EncodeToString(hasher.Sum(nil))
dest, err := os.OpenFile(filepath.Join(this.opts.DataDirectory, fileID), os.O_CREATE|os.O_WRONLY, 0600)
if err != nil {
if os.IsExist(err) {
return fileID, nil // hash matches existing upload
}
return "", err
}
defer dest.Close()
_, err = io.CopyN(dest, src, int64(srcLen))
if err != nil {
return "", err
}
// Determine mime type
ctype := hdr.Header.Get("Content-Type")
if ctype == "" {
ctype = mime.TypeByExtension(path.Ext(hdr.Filename))
}
if ctype == "" {
ctype = `application/octet-stream`
}
// Blacklisted mime-types
ctype = strings.ToLower(ctype)
if strings.HasPrefix(ctype, `text/html`) ||
strings.HasPrefix(ctype, `application/javascript`) {
ctype = `application/octet-stream`
}
// Persist metadata to DB
m := Metadata{
Filename: hdr.Filename,
UploadTime: time.Now(),
UploadIP: UploadIP,
FileSize: srcLen,
MimeType: ctype,
}
err = this.SetMetadata(fileID, m)
if err != nil {
return "", err
}
// Done
return fileID, nil
}